Core D, Biostatistics, is under the Direction of Martin Lesser of the Biostatistics Group at North Shore University Hospital. This Core has essentially two functions: first, to provide standard biostatistical support for tumor and marker studies to be carried out in the Projects; and second, in collaboration with the Genomics Core, to provide incisive analysis and integration of the microarray databases. As regards the latter, Lesser and Augenlicht's groups are already highly interactive in construction and analysis of microarray data bases through their joint funding by an NCI Director's Challenge grant whose goal is to use microarray expression analysis and other transcriptional imaging methods to develop markers, and understanding of the underlying mechanism, of relative sensitivity and resistance to chemotherapeutic agents. Through this mechanism, the groups have developed iterative and exploratory approaches for analysis of such complex databases.